Railway traffic controlling apparatus



June 9, 1936. c. WVFA ILOR RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Aug. 26, 1933 2 Sheets-Sheet 1 @WQQQ INVENTOR Charles W. Fallon. BY Z HIS ATTORNEY June 9,1936. c. w. FAlLOR 2,043,740

- RAILWAY'TRAFFIC CONTROLLING AP ARATUS Filed Aug. 26, 1955 2 Sheets-Sheet 2 CODEA or'B /4 CODE 6 v I I I I 0! v Cami/6 @125 D 7 8 CODE D HIS ATTORNEY Patented June 9, 1936 ,um' sn STATES PATENT OFFICE RAILWAY, .TnAFFIooonrnoLnmo l rrlmsros Charles W. Failor, Forest Hills, Pa., assignorto *The Union Switch & Signal Company,Swiss- 'v'ale, Pa., a corporation of Pennsylvania Application Augustgfi, 1933, SerialNo. 686,970 7 20 Glaims. (Cl. 246-34) My invention relates to railway trafiic controlling apparatus, and more specifically to apparams for providing broken-down insulated rail joint protection in trafiic governing systemswhich uti- ,5 lize coded rail current for controlling wayside and/or cab signals.

I will describe three formsof railway trafiic controlling apparatus embodying my invention,

and will then point out, the novel featuresthere- .10 i of in claims.

2. obtainable through the staggering of polarities of adjoining trackcircuits. This method is, how- .ever, of no avail in the case of circuits using the more simple and less expensive single element, two position track relay. The present invention .12 is directed to the provision of complete brokendown rail joint protection,.irrespective of. traflic conditions, in coded wayside and cab signaling systems, the track circuits of which employ the single-element code-following track. relay. 30 -Since staggered polarities cannot :be usedadvantageously in track circuits of thistype, I propose to stagger certain elements of thecode supplied to adjoining track circuits and to'pr'ovide apparatus distinctively responsivetothetwoltypes of code, thereby preventing thedisplay of false clear signals. With this arrangement, should the I code of one track section pass over defective rail joints into the adjoining section, a restrictive signal will be displayed.

In carrying out the purpose-of my invention, adjoining track circuits are supplied with currents of distinctive character. Obviously, the particular type of current which may beused as the carrier, and upon which may beimpressed the characteristic which renders adjoining track circuits distinguishable from the'sta'ndpoint of the code-following track-relay isimmaterial. For example, numerous codes met within-the signaling art, such as the frequency code, count code, polarity code, time code to name only a iewjcan be modulated insuch a manner as to provide dis- .tinctive response in adjoining track.circuits, for the purpose of broken-down rail joint detection.

In order not tocomplicate-the disclosure'unduly -I havechosenbut two types of code, for

in the code.

of railway trackudivided into sections -|:-2 and" purposes of illustration, these being the frequency code, illustrated at A, Band C of Fig. 1, andthe time code shown at D and E of the same figure.

Referring to- Fig. Lcode C is the usual frequency code used in systems of wayside and cab signaling and comprises, ordinarily, an alternating Icurrent carrier '.of any suitable frequency, upon which are impressed periodic variations occurring at the rate, for example, of 180, 120 or 80 per minute; as determined by trafiic, condil0 ,tions. These variations can be impressed upon a direct current carrier with like effect.

Code A differs from code C only in that a relatively long on interval is interposed periodically This can be readily accomplished in a motor-driven cam type, of code transmitter by mutilating that portion of the contact-operating cam which forms certain of the oil code intervals, such as are shown dotted at a. Code A will be applied to agiven track section, and it ,2 will be understood that the codes of otherperiodic frequencies, whichmay Ice-supplied to this track section under difierent traffic conditions, will be similarly modified by means of a long fon interval. .25

, Code -B.is similar to code A but instead of having a periodically recurrent-longflonj. interval, thiscode has aperiodically recurrent long ofi interval. Code B is intended to be supplied to the track section adjoining the sectionsupplied with code A. The long ofi interval of code B can likewise be readily obtained by mutilating the code transmitter cam to eliminate the on intervalsshown dotted at b.

Codes D and ,E are time codes having long on,

,short, off, and short nj, long 01f intervals,

respectively. 'I'hesecodesmay be used alternately1in adjoining track sections in territory equipped ,for wayside signaling only, or for both waysideand cab signaling, providedthat the 10- comotive equipment which, is used is of such character as to beoperative on impulses of the time code.

Referring now to Fig. 2, I have shown a stretch 23,. each of I which is normally. supplied with coded alternating currentby means of a track transformer designated by the reference character T, with .an exponent corresponding to the location.' The normal trafiic direction is from 0 left to right, as" indicated by the. arrow. It will be noted that the .codes of. adjoining tracksec- .tions are staggered, that is, the section immetion 2-3 with code A, and the section immediately to the right of location 3 is supplied with code B, these being the codes represented diagrammatically in Fig. 1.

The operation of the apparatus will first be explained with reference to section 23. With no train present, the rails of I this section will normally be supplied with coded. current from transformer T resulting in operation of the code-following track relay TR in step with the code. Relay TR is of the direct current type, and is energized through the relay transformer RT and rectifier R the condenser C and reactor X being used to exclude propulsion current and foreign current of non-signaling frequencies. If relay TR is of the alternating current type, it may be connected directly with the rails, eliminating the auxiliary apparatus.

It will be assumed that the periodic frequency of code A is either 180, 120 or 80 per minute, according to the condition of traffic in advance sections. Relays F and E are frequency selective and are responsive, respectively, to the 180 and the 120 code. The energization of these relays is obtained in the customary manner, by converting direct current from a source B C applied over contacts 9l0 and 9H of relay TR into'alternating current in the secondary of decoding transformer DT The output of transformer D1 is supplied to the usual decoding units DE and DF which comprise a condenser and a reactor tuned to the desired code frequency, as well as a rectifier if relays E and F are of the direct current type as is commonly the case. The energizing circuits for relays E and F have not been shown in detail, since these circuits are the same as are commonly used in code systems of cab signaling, and are well-known.

Relays TRP TF and H are controlled through the operation of contacts I2|3 and l2I4 of relay 'IR and in the present disclosure, these 'relays take the place of the usual 80 code relay.

The release time interval of relay TRP is so adjusted that this relay, having a pickup circuit over back contact I2l4 of relay TR will remain energized as'long as relay TR is following the ordinary impulses of the 180, 120 or 80 code frequencies, but will release during the periodically recurrent long on impulse which is the distinguishing characteristic of the 180, 120 and 80 codes comprising code A. The release interval of relay TP is such that the periodic opening of front contact l5-l6 of relay 'I'RP will not deenergize this relay. Also, relay H is suificiently slow acting to insure that the periodic closing of back contact l5l1 of relay 'IRP will maintain relay H in its energized position.

When the code supplied to transformer T is either 180 or 120, code transmitter GT will supply 180 code to transformer T for the rear track section |--2, from a suitable alternating current source BXCX, over a circuit which includes the front contacts l8-l9 and 2I22 of relays TP and H as well as front contact 24-25 of relay F or alternatively, front contact 2128 of relay E and back contact 24-26 of relay F according as relay TR is following 180 or 120 code, respectively. If transformer T is supplied with 80 code, transformer 'I will receive 120 code over back contacts 21-29 and 24-26 of relays E and F and front contacts 2l-22 and l8-l9 of relays H and TP Consequently, as long as relay TR is following any one of the code frequencies embraced within code A, the rear section l2 will receive either 120 or 180 code.

When a train enters section 23, relay TR and therefore relays TP and H will become deenergized, and the 80 or restrictive code will be furnished to transformer T The indications of signal S are controlled by 5 the relays TF H E and F in accordance with the code received by relay TR The specific signal control circuits are not shown, as these are in accord with usual practice. Similarly, the indications of signal S are controlled by the 10 decoding relay group for section l2.

Considering section l-2 which is supplied with code B having a long oif interval recurring periodically in the code, it will be noted that in this case, relay TRP is controlled over a front rather than a back contact of the code-following track relay in order that relay 'IRP will have an opportunity to release during each long oif interval, in the same manner that relay 'IRP of section 23 was permitted to release during each long on interval of code A. The control of relay H is identical with the control of relay H that is, relay H remains energized provided that relay TR and consequently relay TRP follows the long 01f period in the code at intervals which recur within the release period of this relay. To explain the manner in which the circuit functions to provide broken-down rail joint protection, let it be assumed that section 23 is occupied, so that signal S will display its most 3 restrictive indication, and that while section 23 is so occupied, the rail joints at location 2 are broken-down, permitting relay 'I'R to become energized and to follow code B which flows over the rail joints from section I-2. The code frequency of code B, under this traific condition will be 80. Were no protection provided, this 80 code might energize the 80 code relays of section 23, stepping up the code supplied to section l--2 from 80 to 120. Thereupon, the 120 40 code relays of section 23 would respond to step up the code for section l2 to 180, which code when applied behind the train in section 23 might result in a false clear indication at signal S However, because of the absence of the long on interval in code B, relay 'IRP will not be deenergized periodically, thus providing no energizing impulses for relay H as a result of which relay I-I will remain deenergized. Therefore, the code frequency supplied to section l-2 will remain at 80, and signal S will continue to indicate the occupied condition of section 23.

If 80 or 120 code is being fed to section 23 at the same time that 120 or 180 code is being fed to the rear section l-2, and the rail joints break down, relay TR will be following an irregular code, the resultant of codes A and B, which will ordinarily keep this relay energized almost continuously. If the code transmitters CT and CT are of the induction motor type and are not synchronized, beat notes will usually occur, resulting from the two codes occasionally passing in and out of synchronism. Therefore, one or the otherof relays TP or H will pick up or release occasionally, according as the two codes A and B tend, at the moment, to annul or to aid each other, resulting in an occasional flashing indication being obtained at signal S which aids detection of the faulty rail joint.

The manner in which relay TR operates on code B and provides protection against improper signal operation by code A from an adjoining section is as follows: It will be noted that relay TRP is energized over a front contact of relay .TRg and since code B has a long 01f interval,

off intervals.

the release interval of relay TRP each time that relay TRP releases, relay TPP --relay lTRP will be "deenergized at :each long off interval, "thereby maintaining the slow-releaszing relay Hlconstantly picked:.up. Therelease time of relay TP is sufficient to'bridge the revleaseperiod of relay TRP so that normally,

-relay.:TP .also remainslpicked up. If code A from an adjoining section either forwarder in the rear of: section |2 should flow in the rails of .the section, the absence of the long off-interval wouldprevent relay TRP from releasing periodically, thus causing relay H to release, and insuring the display of a restrictive indication at signals S It will be apparent from the foregoing description that by staggering the codes which are ap- 'plied to adjoining track circuits, complete broken-down rail joint protection can be obtained. The released condition of relay H or relay H mayjof itself, be used to provide an indication that-the rail joints at location I or 2 are brokendown.

In'Fig. 3, I have shown how a standard code such as code C of Fig. 1, can be staggered with either of codes A or B, to provide the desired protection. Referring to Fig. 3, the decoding apparatus of this figure is similar to the standard decoding group used in frequency code systems of signaling with the exception that the usual Ml-code relay is replaced by the two relays TF and H When relay TR is operating on code C; both relays TF and H remain constantly energized. Should code A from an adjoiningsection energize relay TR, the long on interval of this code would cause relay TP to release periodically, to cause flashing of the signal. If relay TR is'energized by code B, the long off "interval of this code will similarly cause relay H to release periodically, and to flash the signal.

Referring to Fig. 4, the circuits shown therein illustrate one way in which the principle of code staggering can be applied to a signaling system employing the time code, of which codes D and E of Fig. 1 are representative. To simplify the disclosure, direct current from a suitable battery source is used as the carrier-for the code, instead of alternating current, and but one form of the characteristic code is supplied per track circuit by code transmitters CT, it being understood that for multiple aspect signaling each of codes D and E would in practice comprise modifled forms based on different time ratios between the on and off intervals, for providing distinctive signal aspects in accordance with traflic conditions. Track sections 6-1 and -'l-8 represent cut sections within a block, and the block signals and associated control circuits are omitted from the drawings as these are not essential for an understanding of the invention.

Considering section 1-8, the code supplied to "track relay TR by code transmitter CT is code 'E' of Fig. l, and comprises relatively short periodic on intervals separated by relatively long Relay TRP" is so designed that it will release during each long off interval of the code, and relay TP is designed to bridge Therefore,

will receive an impulse of energy, which will maintain relay TPP' constantly picked up, keeping the signal control circuit closed at front "c0ntact'30. Should relay 'IR. become accidentallyi'energized by code D fromthe adjoining section, the short duration of the "off interval of codeDwould prevent relay TRP' from releasing.

Therefore; relay TPF "would become deenergized .and would open the signal circuitiat'eontactjfl, to provide the necessary protection.

Insection 6-1, relay TRP is designed:to.=release during each long on interval: of code .D, and relay TP is sufficientlyslow-acting to bridge 5 the releaseinterval of relay 'I'RP Therefore, relay TPP will be maintained in its energized position by virtue of the periodic impulses of energy which it receives each time that the had; contact of relay TRP is closed. As atresult, the signal control circuit will be maintained closed at front contact 3|. The manner in which relay TPP will release the open contact 3!, should code E from an adjoining section falsely operate relay TR will be clear without added description. I

It will be understood, ofcourse, that the staggered .codes of a given stretch of track .need'not belong to one group, such as the frequencycode or the time code group, because one traek.1eircuit may be supplied with frequency code, such as code A, B, or C, and the adjoining track circuit with time code, such as code D or E, provided that decoding apparatus distinctively responsive to the particular code for the section be used.

Although I have herein shown and described only a few forms of apparatus: embodying'my invention, it is understood that various changes and modifications may be made therein within the scope oftheappended claims without departing from the spirit and scope of my invention.

Having thus described my invention,what' -I claim is:

1. Apparatus for providing broken-down-insulated rail joint protection comprising, in combination with two adjoining sections of railway track, means for supplying one of said sections with a plurality of'different coded train governing rail currents upon at least one of which are 40 impressed periodically recurrent variations according to a first pattern, means for'supplying the other of said sections with a plurality of different coded train governing rail currents upon at least one of which are impressed periodically recurrent variations according to a second pattern, and decoding apparatus for each of said sections selectively responsive to said coded currents according as the variations thereof conform to said first or said second pattern.

2. In combination, two'adjoining sections of railway track, means for supplying one of-said sections with a plurality of different codedrail currents at least one of which is variedin a first periodically recurrent manner,- means for supplying the other section with a plurality of difierent coded currents at least one of which is varied in a second periodically recurrent manner, a signal for each of said sections, adecoder for each of said sectionsfor governing the'signal associated therewith and selectively responsive to the codes supplied to its respective section, and means governed by each decoder for preventing a permissive indication of the associated signal in the event that the decoder becomes, operated by coded rail current varied in the periodically recurrent manner from the adjoinin section.

3. In a code system of railway signaling; the method of preventing the display of false signal indications resulting from feed-over around irisulated rail joints, which comprises supplying to ratus selectively responsive to said codes for each track circuit, whereby a permissive signal indication will be given when said apparatus responds to codes supplied to the track circuit associated therewith, and a restrictive indication will be given when said apparatus .responds to the alternated code from the adjoining track circuit.

4. In combination, a stretch of railway track divided into track circuit sections, means for supplying a plurality of codes of a given time pattern to alternate sections of said stretch, means for supplying a plurality of codes of a second time pattern to intervening sections of said stretch, decoding means for said alternate sections dis- .tinctively responsive to codes of said given time pattern, decoding means for said intervening sections distinctively responsive to codes of said second time pattern, and trafiic governing apparatus controlled by the decoding means for said alternate and said intervening sections.

5. In combination, two adjoining sections of railway track one of which is supplied with coded rail current having a first characteristic code interval which recurs at given periodic times and the other of which is supplied with coded rail current having a second characteristic interval which recurs at said given periodic times, a code-following track relay for each of said sections, and a decoder for each of said sections controlled by the track relay associated therewith in such manner as to assume one or another condition according as the track relay is following coded rail current having said first or said second characteristic interval, respectively, whereby the condition of said decoder indicates whether the track relay is following rail current supplied to the section associated therewith or rail current supplied to the adjoining section.

6. In combination, a first section of railway track, a second section of railway track adjoining. therewith, means for supplying said first section with a code having a periodically recurrent on interval of relatively long duration, means forsupplying said second section with a code having a periodically recurrent off interval of relatively long duration, and a signal governing decoder for each of said sections responsive to said codes in such manner as to assume a signal governing condition in response to the code supplied to its respective section but to assume an inoperative condition in response to the code supplied to the adjoining section.

'7. In combination, a section of railway track supplied with a code upon which is impressed a periodically recurrent characteristic interval of relatively long duration, a code-following track relay for said section, a first relay controlled by said track relay in such manner as to remain energized at all times except when the track relay is following said characteristic interval of the code, a second relay controlled over a front contact of said first relay and capable of bridging the deenergized interval of said first relay, a third relay controlled over a back contact of said first relay and capable of bridging the energized interval of said first relay, and trafiic governing apparatus controlled by said second and third relays.

8. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with a code having a periodically recurrent on interval of relatively long duration, means for supplying said second section with a code havinga periodically recurrent off interval of relatively long duration, a code-following track relay for each of said sections, a control relay for said first section governed by the associated track relay in such manner as to maintain its energized condition provided the code supplied to said first section contains said periodically recurrent on interval, a control relay for said second section governed by the track relay associated therewith in such manner as to maintain its energized condition provided the code supplied to said second section contains said periodically recurrent off interval, and traffic governing apparatus controlled by each of said control relays.

9. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with one of a first group of codes selected in accordance with traffic conditions in advance of said first section, each code of said first group being characterized by a periodically recurrent on interval of relatively long duration, means for supplying said second section with one of a second group of codes selected in accordance with trafiic conditions in advance of said second section, each code of said second group being characterized by a periodically recurrent off interval of relatively long duration, decoding apparatus for said first section selectively responsive to codes of said first group as well as to the presence of said periodically recurrent on interval in said codes, decoding apparatus for said second section selectively responsive to codes of said second group as well as to the presence of said periodically recurrent off interval in said codes, and trafiic governing apparatus controlled by the decoding apparatus for said first and said second sections.

10. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with a plurality of coded rail currents, means for supplying said second section with a similar plurality of coded rail currents upon at least one of said currents is impressed a periodically recurrent characteristic variation, a signal for said first section, a decoder for said first section selectively responsive to said coded rail currents, and means governed by said decoder for preventing the display of a permissive indication by said signal in the event that said decoder becomes operated by the coded rail current supplied to said second section, and having said periodically recurrent characteristic variation impressed thereon.

11. In combination, a stretch of railway track divided into track circuit sections alternate ones of which are supplied with rail current of a given code and intervening sections of which are supplied With rail current of said given code modified by a periodically recurrent characteristic variation, and decoding apparatus for each of said alternate and said intervening sections capable of assuming one condition when energized by said given code and another condition when energized by said given code as modified by said characteristic variation, whereby the condition of said apparatus provides an indication of the integrity of the insulated rail joints between said alternate and said intervening sections. 12. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with rail current of a given code, means for supplying said second section with rail cur,-

rent of said given code upon which is impressed a periodically recurrent characteristic variation, a code-following track relay for said first section, a control relay governed by said track relay in such manner that said control relay will assume one condition when said track relay is following said given code and another condition when said track relay is following the code supplied to said second section, and traflic governing apparatus controlled by said control relay.

13. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with a plurality of coded rail currents comprising substantially uniform periodic on intervals separated by substantially uniform off intervals of relatively shorter duration, means for supplying said second section with a plurality of coded rail currents comprising substantially uniform periodic ofi intervals separated by substantially uniform on intervals of relatively shorter duration, a decoder for each of said sections selectively responsive to the coded currents supplied to the section associated therewith, and traffic governing means controlled by said decoders.

14. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with coded rail current of a first code comprising substantially uniform periodic on intervals separated by substantially uniform off intervals of relatively shorter duration, means for supplying said second section with coded rail current comprising substantially uniform periodic ofi intervals separated by substantially uniform on intervals of relatively shorter duration, a code-following track relay for said first section, a first relay controlled by said track relay in such manner as to remain energized during the off periods of said first code and to become deenergized during each on period of said first code, a second relay controlled over a front contact of said first relay and capable of bridging the deenergized interval of said first relay, a third relay controlled over a back contact of said first relay and a front contact of said second relay and capable of bridging the energized interval of said first relay, and a traflic governing apparatus controlled by said third relay.

15. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying rail current of a first and of a second code to said first and said second section respectively, a code-following track relay for said first section, and means controlled by said track relay effective for preventing the supply of rail current of said second code to said second section if said track relay is following said second code.

16. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying rail current of a first and of a second code to said first and said second section respectively, a code-following track relay for said first section, and a protection relay controlled by said track relay and effective for preventing the supply of rail current of said second code to said second section if said track relay is following said second code.

17. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with rail current varied according to a first code, a code-following track relay for said first section, a decoding relay controlled by said track relay, a source of current varied according to a second code, a protection relay controlled by said track relay and said decoding relay in such manner as to assume one condition when the track relay is following current varied according to said first code and another condition when the track relay is following current varied according to said second code, and means controlled in accordance with the condition of said protection relay for supplying current from said source to the rails of said second section.

18. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with a first code having a periodically recurrent on interval of relatively long duration, means for supplying said second section with a second code having a periodically recurrent off interval of relatively long duration, a code-following track relay for said first section, a decoding relay controlled by said track relay, a protection relay controlled by said track relay and said decoding relay in such-manner as to assume a first or a second condition according as said track relay is following said first or said second code respectively, and means effective when the protection relay occupies said second condition for preventing the supply of said second code to said second section.

19. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying said first section with a first code having a periodically recurrent on interval of relatively long duration, means for supplying said second section with a second code having a periodically recurrent off interval of relatively long duration, a code-following track relay for said first section, a decoding relay controlled by said track relay, a protection relay energized over a front contact of said decoding relay and having a release time insufiicient to bridge the long off interval of said second code, and means effective when the protection relay is deenergized for preventing the supply of said second code to said second section.

20. In combination, a first section of railway track, a second section of railway track adjoining therewith, means for supplying rail current of a first and of a second code to said first and said second section respectively, a code-following track relay for. said first section, a protection relay, a decoding relay controlled over a front contact of said protection relay, means for controlling said protection relay by said track relay, said protection relay being designed to remain energized if the track relay is following said first code but to release if said track relay is following said second code, and means controlled by said protection relay for governing the supply of said second code to said second section.

CHARLES W. FAILOR. 

